Picture projector



July 9, 1940.

B. c. HAsKlN PICTURE PROJECTOR Original Filed April l1, 1938 4 Sheets-Sheet l INVENTOR. BYPa/y C. HAsK//v ATTORNEY.

July 9, 1940. B. c. HAsKfN 2206,953

PICTURE PROJECTOR Original Filed April 11, 1938 4 Sheets-Sheet 2.

INVENTOR.

BY BYPo/v C. HAsK/N ATTORNEY.

July 9, 1940. B. c. HASKIN 2,206,953

PICTURE PROJECTOR Original Filed April l1, 1938 4 Sheets-Sheet 5 11111111/111vll/11111111111111111111111111,111,111,1/1

' ATTORNEY.

July 9, 1940.

- B. C. HASKIN PI CTURE PROJECTOR original Filed April 11, 1938 4 sheets-sheet 4 @ggg -ml l lll/11111111111111111111. rllI/lll/Lfl INVENTOR.

ATTORNEY.

Patented July 9, 1940 UNITED A STATES PATENT oFFlcE to Warner Bros.

Pictures, Inc., New York,

N. Y., a corporation of Delaware Original application April 11, 1938, Serial No. 201,372. Divided and this application October 8, 1938, Serial No. 233,972

4 Claims.

The invention provides a means for rigidlyl supporting the objective lens of a projector independently of the body of the projector while permitting movement of the projectorbody rtoward and away from the lens for focussing. With this arrangement the adjustment of the projector to cause the image projected thereby to assume a given size on a screen is facilitated since theV magnification of the projected image is determined by the distance between the lens and the screen. Having correctly positioned the lens relative to the screen, it is a simple matter to move the projector body toward or away from the lens until the image is in sharp focus on the screen. The invention further permits reduction of the well known keystone or distorted eiect due to the projection of a picture at an angle upon a screen surface by the provision ofl meansfor angularly adjusting the projector body containing the film to be projected relative to the objective lens therefor while maintaining the lens in a fixed position relative to the screen. By causing the axis, about which the projector body is angularly movable, to pass centrally of the film and in the plane of the emulsion surface of the lm, no image sweep will result when the projector is adjusted for keystone.

Another feature of the invention lies in the provision of means for supporting theobjective lens of a movingpicture projector independently ,of the projector body thereof, thereby to reduce the tendency of any vibrations generated bythe various lm driving elements in the projector body from being transmitted to the objective lens with consequent vibration of the picture image projected on the screen.

All of the above features are of especial importanc'e in the case where a plurality of projectors are arranged to project identical superposed pictures on a screen for the purpose of increasing the brilliancy and/or the magnification of a picture as disclosed and claimed in the co-pending application of Byron C. Haskin, Serial No. 201,372,

filed April l1, 1938, now Patent No. 2,198,815, April 30, 1940, for Composite photography,lof which this application is a division. In that case even a slight relative vibration or misalignment between the superposed images is objectionable 5V since `it causes the resultant or composite picture appearing on the screen to lose its sharpness and, in the case of color pictures, mayv cause a `color fringe to appear in the projected picture.

The manner in which the above and other objects of the invention areaccomplished will be `readily understood on reference to the following specication read in conjunction with the accompanying drawings wherein: I

Fig. l is a front elevational view of a projector unit embodying the present invention.

, Fig. 2 is a sectional elevational view takenv along the line 2-2 of Fig. 1.

Fig. 3 is a sectional planview through the support for the rear projector lamp house and is taken along the line 3 3 of Fig. 2. Fig. 4 is a fragmentary sectional view of the 'rear projector lamp house adjustment `and is taken along the line l-lI of Fig. 3.

Fig. 5 is a sectional elevational View, with parts broken away, and is taken along the vline 5 5 of Fig. 2.

Fig. 6 is a sectional view taken S-S of Fig. 5.

Fig. '7 is a sectional view through the pan adjustment of.one of the projectors and is taken along the line 'I-JI of Fig. 5.-

Fig. 8 is a transverse sectional View through kone of the objective lens mounts and is taken along the line 8*-8 of Fig. 1.

Fig. 9 is a sectional view through oneof'the take-up reel magazines and support therefor and is takenalong the line 9-9 of Fig. 5. Fig. l0 is a fragmentary, sectional along the line Ill- Ill of Fig. 5.

Referring to Figs. 1 and 2 in particular, the apparatus comprises generally a pair of opposed motion picture projectors Ill and II having their optical aXes in alignment with each other. A- third projector I2 is situated at right angles to both of the projectors IU and I! and has the optical axis thereof intersecting the optical axes of the opposed projectors. Mirrors I3 and I4 individual to the projectors It and II, respectively, are-provided to deflect-the light beams therefrom in a direction substantially parallel to the light beam emitted by the projector I2. These mirrors I3 and I4 are preferably so adjusted that the light beams deected thereby intersect each other. and the light beam from the projector I2 along the' une view taken at a screen surface so as to produce, when identical films are employed in the projectors I0, II and I2, a single picture with substantially three times the brilliancy of that obtainablefrom any one projector.

The projectors I8, and I2 are identical with each other, each comprising generally a projector body 22, a film supply magazine 23 thereon, and a motor 25 for driving the various film actuating mechanisms therein. Objective lenses 26, 21 and 28 mounted in lens tubes 26', 21 and 28', respectively, for the projectors I0, I| and I2, respectively, are supported independently of those projectors by three lens mounts 29 mounted on a casting 38. These lenses are optically matched with each other to permit equal magnification of the three projected images and to permit ready interchangeability without correcting various adjustments. Casting 3U is secured on top of a ,T-shaped projector bed or base 3|, also forming a support for the various projectors. Projector bed 3| is supported upon a pedestal 32 for movement about a tilt axis passing through the centers of mirrors I3 and I4 which, incidentally, coincides with the aligned optical axes of the projectors I8 and II through a bearing assembly, generally indicated at 33. The bed 3| has a depending saddle 34 (Figs. 5 and 6) formed centrally thereof. Each leg 5 and 6 of the saddle 34 has a pair of segmental bearing strips 35 and 36 secured to the inner surface thereof by screws 31. These bearing strips are each concentric with the above described tilt axis and are received within arcuate bearing grooves 38 and 39 also concentric with the optical axes of projectors I9 and II. These grooves 38 and 39 are formed in a head casting 40 secured by bolts 4| to the top of the pedestal 32. A lock screw 42 extends through an arcuate slot 42', concentric with the strips 35 and 36, in the leg 6 of the saddle formation 34 and is threaded in the head casting 48 to clamp the projector bed 3| in different tilted positions. A Worm gear segment 43, concentric with the above described tilt axis is secured to the saddle leg 6 by bolts 44. Worm gear segment 43 meshes with a worm 45 rotatably carried in bearings 46 and 41 (Fig. 2) integrally formed on the head casting 40. A hand Wheel 48 is provided to rotate the worm to tilt the projector bed 3| and projectors -V trally in the base 5 I.

bearings 56 and 51 supported within the pedestal thereon.

Pedestal 32 has an annular bearing surface 49 formed on the bottom thereof which is received on a corresponding bearing surface 50 formed on a main base 5| to permit rotation of the pedestal 32 and bed 3| about a vertical axis intersecting the intersection of the optical axes of projectors I0, I| and I2. The base 5| is secured to a floor 52 by bolts 53. A tubular column 54 extending axially of the pedestal 32 is secured at its lower end within a hollow boss 55 formed cen- Column 54 extends through 32 by radially extending flanges 58. The upper end of the column 54 is threaded to receive retainer nuts 59 to hold the pedestal 32 on the base 5| while permitting relative rotation therebetween.

is concentric with the axis of rotation of the pedestal 32 and meshes with a worm 63 rotatably supported in spaced bearings 64 and 65 suitably secured to the base 5|. A hand wheel 66 is provided to rotate the worm 63.

Referring now to Fig. 8 the objective lens mount 29 for each of the objective lenses of the three projectors comprises a bracket 69 rigidly secured to the casting 3U. The upper end of the bracket 69 is formed into a semi-circular lens receiving surface to receive the lower half of a sleeve 1U carrying lens tube 21 in which the various elements of the objective lens 21 are mounted. A semi-circular cover 1| is hinged at 1I' to the bracket 69 and is adapted to clamp the sleeve 10 and its lens tube 21 in fixed position by means of a clamp screw 12. Screw 12 is pivotally secured at one end thereof to a pin 13 extending between a pair of spaced lugs 14 formed integrally with the bracket 69. A nut 15 threaded on the upper end of the screw 12 is adapted to bear against a pair of spaced lugs 16 on the cover 1| thus holding the cover in a clamped position. A key 11 carried by the bracket 69 and projecting into the semi-circular groove formed in the bracket 69 is provided to engage a corresponding notch in the sleeve 10 to facilitate correct positioning of the objective lens.

As shown in Fig. 5 the lens tube 21' is locked against longitudinal movement in the sleeve 10 by a dowel pin 1D. The other lens tubes are similarly locked in these respective sleeves 10.

In the original adjustment of the various objective lenses 26, 21 and 28, prior to the insertion of the dowel pins 10', each of the lens tubes 26. 21 and 28' is slid along its respective sleeve 'I8 until equal magnication is obtained for all lenses. The dowel pins 10 are thereafter passed through the lens tubes and their respective sleeves 'I0 to permanently retain the same in their correctly adjusted positions. Thereafter the magnification of all the lenses 26, 21 and 28 will be uniform thus facilitating focussing adjustment. l

As will be noted in Fig. 5 the objecti e lens tube 21' carrying the objective lens 21 of the projector extends freely Within an aperture 19 formed L -in the front wall 8U of the projector to permit projector II to be moved relatively to the fixed sleeve 10 for focusing purposes, Without light leakage.

The above arrangement of the three projectors I0, II and I2 and their respective objectivelenses 26, 21 and 28 provides a rigid support for all of the lenses without any metallic connection between the proje'ctor bodies 22 and their lenses and lens mounts except through the heavy base l their accurately aligned objective lenses.

The mirrors I3 and I4 are preferably of the front surface type such as obtained by employing highly polished stellite plates and are supported in adjustable mounts generally indicated at 8| whereby the mirrors may be adjusted about vertical axes to cause the projector light beams from the projectors Il) and I I to be moved laterally with respect to the light beam from the projector I2.

Each of the three arms of the T-Shaped bed 3| has a dovetailed guideway |80 (Figs. 5, '1 and 9) extending longitudinally thereon to slidably receive a slide IUI. Slide |0| has a depending projection |82 integrally formed thereon which extends through an elongated slot |03 in the bed 3| and has threaded therethrough fa screw |00. Screw |04 is journalled at either end thereof in bearings |05 and |06 depending from the base 3|. A bevel gear |01 secured on the screw |04 meshes with a second bevel gear |08 carried on a shaft |03 journalled in bearings ||0 and depending from bed 3|. A hand wheel ||2 on the shaft |09 permits manual focusing adjustment of the projector. f

Each projector is adjustable about a vertical axis passing through the center of the plane of the emulsion surface of the film in the lm gate vE I3 (Fig. 5) thereof to compensate for any possible keystone eifect of the projected images therefrom. A pad ||4 secured to the bottom of each projector by screws 1| has a vertical pin i5 journalled therein and securedto the slide lui. Pin ||5 is situated with the axis thereof passing centrally through the plane of the lm F in the nlm gate ||3 to permit movement of the projector therearound. The projector is movable about the pin ||5 through an adjustment generally indicated at H6 (Fig. 7). ment comprises a transversely extendingscrew ||1 threaded within a projection ||8 extending upwardly from the slide Screw ||1 abuts at either end thereof against a pair of spaced lugs i9 and |25 integrally formed on the projector pad H4. A turret |2| secured on vthe screw||1 is provided to permit manual rotation ofthe screw ||1 for adjustment of the projector about the pin H5. Clamp. screws |22 and |23 extend through elongated slots |24'and |25, respectively,

in the pad ||4 and are threaded in slide |0| to lock the pad `H4 onto the slide |0|. Slots |24 and |25 are formed concentric with pin H5.

Referring now to Figs. and 9 the take-up reel of each projector is supported by the bed 3| independently of its respective projector.' The reel |25 is removably keyed on a spindle |26 journalled in a bearing |21 formed in a take-up magazine |23. Magazine |28 is supported from the under surface of a projection of the bed 3| by a bracket |29. Reel |25 is driven by a pulley |30 on shaft |26, deriving its rotation from a pulley (Fig. 1) through a continuous flexible belt |32. The pulley |3| is suitablygconnected in the usual manner to the film drivingl mechanism in the projector.

The film F enters the take-up magizine |28 v through aY fire trap comprising two pairs of wringer or guide rollers |33, |33', |34 and i3d'. The upper pair of rollers |33 and |33 are rotatably supported on pins carried on a bracket |35 (Fig. 9) mounted on the bed 3|. The lower rollers |313- and |34 are rotatably mounted on pins extending from the wall of the-magazine |28. The outer end of each pair of ivringer rollers are free to permit the film to be passed transversely therebetween when threaded.

The film is drawn through the picture gate ||3 of the projector by means of a pull down mechansm generally indicated at |31 (Fig. 5). Pull down mechanism |31 is preferably of thel type 'i employing pilot or register pins to permit accurate and steady registration of the film F While it is intermittently held stationary in the lm gate HS. From the kpull down mechanism |31 the nlm is passed around a hold back sprocket |38, over a guide roller |39, and thence between the two upper wringer rollers |33 and |33 of the takeup magazine fire trap. Roller |39 isrotatably mounted in the body of the projector and extends through an opening |40 in the rear wall Ml of the projector thus guiding the film Ffrom the This adjustvsecured thereto and to the pedestal 32 projector to its take-up magazine in all focused positions thereof. A channel shaped cover member |02 is provided to protect the film passing between the roller |353` and the magazine |23. Cover |42 is pivoted on a pin |33 (Fig. 10) projecting `from a bracket |43 suitably secured on 1 the base of the guideway |00 and is adapted to be swungoutward to permit threading or inspection of the film. Due to the action of gravity cover |`|2 follows the rear Wall |4| of the projector in all adjusted positions thereof. Ak door 235 hinged at 203 to the magazine |28 permits access to the take-up reel |25. y

An arc light (not shown) is supported ina conventional type of lamp house |35 (Fig. l) for illuminating the film in projector |-i to project an image thereof to the screen. Lamp house |05f is adjustably supported on a downwardly inclined arm |45 secured intermediate its length to a bracket |46 which, in turn, is secured to the side of the pedestal 32. Arm M5 is also supported by track |59 as described later. An adjustment generally indicated at |41 is provided to move the lamp house |44 longitudinally thereof to correctly position the same for positions of the projector l0.

Arm |45 has a hollow skirt |51 formed at the bottom thereof in which is rotatably mounted a pair of rollers, one of which is shown at |53. Rollers |58 `ride along a track |59 integrally formed on the main base 5| to assist in supporting the lamp house IM. Track |53 extends con'- centric with the axis of rotation of pedestal 32.

The arc light for the projector is provided in a lamp house |30, vwhich is supported for longitudinal adjustment as generally indicated at ||i|, the same as the' longitudinal adjustment for the lamp house n |43. Lamp house |60 is supported on the top of an arm |52 secured intermediate its length to a bracket |53 which, in turn, is secured to the side of pedestal 32, opposite the point where bracket |36 issecured thereto. Arm |62 also has rollers, one of which is shown at |65, rotatably mounted in an enlarged skirt |33 tlhereinfor movementalong the circular track It is to be noted that the lamp houses |343 and |60, althoughv movable about a vertical axis through the center of pedestal 32 in xed relation with; their respective projectors, are not rotatable about a horizontal axis with those projectors when hand Wheel 48 is manipulated to tilt the projectors. r

A lamp house' |01, similar to those of HM and |60, carrying anarc light is provided 4for the projector |2. Lamp house |61 is supported on a curved arm |68, concentric with the aligned optical axes of the projectors |ii and through longitudinal adjustment |33 similar to that pro-- vided for lamp houses Mii and |30. Arm |33 (Figs. 2, '3 and 4) is substantially square in cross section and has raised bearing portions |10 at either .corner thereof. Arm |33 is slidable within a curved bearing member -|1I. Member |1| comprises in cross section a U-shaped casting |19 having a cover plate |12 sec red thereto by screws |13 to enclose the arm |53'. Bearing member |1| is supported in part by a bracket |13 mediate the points Where brackets Hi8 and |33 are connected. Member |1| is also supported `from a track |15 by a tubular framework |15 on 4the lower end of which is mounted a pair of rollers |11 and |18 movable along the track |15.

Track |15 is .concentric with track |59 and may y different focusing interv fas be inset in the oor as shown in Figs. 2 and 3. Framework V56 comprises a pair of spaced vertically extending tubular posts 241 and 248 4.attached at their upper ends to either side of the bearing member 1li and terminating at their lower ends in a hollow skirt 249 in which are mounted the rollers 1'1'1 and 1'18.

Means are provided to move the lamp house 16's' in a curved path to align the same with the projector 12 for different positions thereof about the horizontal tilt axis of the projector unit. To accomplish this a curved gear rack 180 is integrally formed along a portion of the arm 168. A gear 181 meshes with the rack 18D and is carried on an axle 182 journalled within bearings 163 and ist formed in a gear casing 185. Gear casing 155 is secured to the outer flange 186 of the bearing member 1'11 by bolts 181 and encloses an aperture 186 formed in the flange 186 to permit the gear 181 to mesh with rack 180. A worm 188 meshes with the gear 181 and has the shaft it thereof journalled within bearings 19D and iti also formed in the gear casing 85. A hand Wheel |92 is provided on the shaft 89 to permit manual rotation of the worm 188 to adjust the lamp house i'l about the horizontal tilt xis of the projector unit.

In operation, the various elements ofthe projector apparatus are adjusted as follows: The rear projector 12 is first illuminated to project a beam of light therefrom onto the screen. The projector base 31 is then panned and tilted by means of the hand wheels 66 and 48, respectively, until the beam of light is centrally located on the screen. This panning movement of base 31 has served to move all the lamps with their respective projectors as the projectors and their lamp houses are moved about a vertical axis when pedestal 32 is rotated by hand wheel 66. However, hand wheel 46 tilts all the projectors without tilting any of their respective lamp houses and lamp house 161 is the only one which must be given a corrected tilt' adjustment (by hand wheel 192) when the projectors are tilted. With the construction shown, there is no necessity for a tilt adjustment of lamp houses 144 and 160 when all the projectors are tilted, as the tilt movement is about an axis passing through optical axis of lamp houses 144, 160 and their projectors. The hand wheel 192 is rotated until the lamp house 151 assumes the correct position relative to the projector I2, that is, until the arc light therein is aligned with the optical axis of the objective lens of projector 12. The arcs for the projectors I and 11 are then lit to project their respective beams onto the screen. The mirrors 13 and 14 are then adjusted roughly to register the two beams from projectors and 11 with the beam trom projector 12.

If the picture scene is to be projected in black and white, three identicalv positive prints from the same negative of the scene are prepared and are threaded in the three projectors. However, if the scene is tobe projected in color according to the additive process, three positive prints are respectively prepared from three color separation negatives of different color aspects of the scene (assuming a three color process is employed) and are threaded in the three projectors, Again, if the scene is to, be projected in color according to the subtractive process, three identical and natural colored prints of the same color negative or set of color negatives of the scene are prepared and threaded in the three projectors.

f The three positive prints regardless of how they are obtained, arev provided with vsynchronized starting marksby which they may all be started Vin the same relative positions in the projectors.

In any of the above cases, after the three projectors are -properly threaded, they are successivelyv illuminated and focused by the hand wheels 112 until theprojected image from each is sharp on the screen. In the final adjustment all three projectorsare illuminated and the' mirrors 13 and 14 are minutely adjusted to obtain exact registration of the three light beams on the screen.

The use of the invention in conjunction with the projection of ordinary black and white silver image films or dyed silver imagey films results in a large reduction of projected silver grain pattern.l This pattern is dueto the clustering of the minute silver grains in the nlm emulsions. ,Since the `arrangement, of the silver grain patternin different films or different portions of the same film is, of course, different, the superposition of several identical and registered projected film images on a screen will result in the projected minute voids or openings caused by .the clustering of grains in one iilm emulsion being lled by the projected images of the minute clustered grains themselves in another film emulsion.` Y

Due to the above noted reduction of grain pattern the details and clearness of the projected picture will be materially increased. Also, due to the reduction of the minute voids in the projected pictures which are caused by the clustering of silver grains in the lm emulsion, the shadows or darkened portions of the projected pictures will be rendered darker resulting in a greater. contrast value between highlights and shadows. This increase in contrast value reduces the washed-out appearance noted in projected background type of composite pictures.

The provision for tilting the projector unit about an axis passing through the centers of the angularly positioned mirrors has the advantage that the lengths of the optical paths between the lms in the various projectors and the projection screen all remain the same for different tilted positions of the projector unit, and therefore the registration of the three projected images from the three projectors remains undisturbed. This feature remains the same regardless of the relative positions of the projectors. That is, if the projectors 11) and 11 were positioned midway between their illustrated positions and the projector I2 (or in any other position) While the mirrors 13 and 14 were adjusted to register the various superimposed projected images, this registration of the various images would remain undisturbed provided that the projector unit was tilted about the axis passing through the centers of the mirrors 13 and 1d.

The importance of the above feature is recognized by the fact that a movement of the order of one inch of the projector unit toward or away from the projection screen will result in the registration of the superimposed projected images from the three projectors becoming noticeably disturbed.

In order to correctly adjust the position of the lamp house |61 for various tilted positions of the projector 12 on bed 31, corresponding scales may be provided on the leg 6 of saddle 34 and on the curved arm 168 supporting lamp house 161 to bring these members into alignment.

I claim:

1. Projection apparatus comprising the combination of a picture gate, film traversing means therefor, a housing for said gate and said means, an objective lens, means independentof said housing for supporting said lens, adjusting means for moving said housing about an axis through said gate, and means for moving said casing toward and away from said lens.

2. Projection apparatus comprising a support, a slide thereon, an adjusting screw for reciprocating said slide, a film projector casing on said slide, said casing having a picture gate fixed therein, means supporting said casing on said slide for pivotal movement about an axis through said gate, and an adjusting screw on said slide for effecting said pivotal movement.

3. Projector apparatus comprising the combination of a bed, an objective lens mount, means for supporting said lensvmount in fixed relation to said bed, a. slide on said bed movable towards and away from said lens mount, means for operating said slide, means for supporting a projector casing in operative relation to said lens mount comprising a pad on said slide, apivotal connection between said vpad and said slide for pivoting said pad about an axis transversely of the axis of said lens mount, and means on said slide for pivotally adjusting said pad.

4. Projector apparatus according to claim 3 comprising a lens tube in said lens mount, a projector casing having a front wall with an aperture therein to receive one ,end of said lens tube, said projector casing having a film` movement and a ilm gate therein,A and means for securing said-casing to said pad'. with said film gate in alignment with said pivotal connection.

BYRON C. HASKIN. 

